1. Technical Field
The present invention relates to a technique for compressing or decompressing image data.
2. Related Art
There is a technique for reducing the amount of data transmission by compressing image data showing a still image or a moving image. JP-A-2012-134847 discloses a technique of performing compression processing using the same compression algorithm for the entire image signal. JP-A-2002-354270 discloses a technique of comparing the data of a plurality of lines after compressing still image data in units of a line and transmitting only the header when the lines of the same data appear to overlap each other.
The invention disclosed in JP-A-2012-134847 is for compressing the entire image signal according to the same compression algorithm. Accordingly, it may be difficult to increase the compression rate efficiently. The invention disclosed in JP-A-2002-354270 is for comparing a plurality of lines after compressing still image data using a run-length compression method or the like and determines which of the still image data after line-unit compression and the header is to be transmitted. Therefore, in the invention disclosed in JP-A-2002-354270, compression processing of the still image data is not performed according to the matching of data of a plurality of lines.